As I look at Keep tonight, it is not yet Evernote. Yet, is very important. I suspect we'll see fast iterations of Keep.
Even though I am not going to use it, I've marked it as one of the web pages I open every day. I suspect we'll see rapid growth in its feature set.
But I think Keep is like Google Now, Google Goggles and some other efforts recently. It is not for the web, or even Android, but rather Google's upcoming Google Glass.
Glass will need an app to capture all the tidbits of information we come across in a day. Those tidbits will be photos, and audio both of which Keep can capture now.
When I first came to understand what Glass was going to be out, me being me, thought what a wonderful capture tool it would be to feed Evernote.
Of course, Google knows that too, but they do not own Evernote, so hence Keep.